FR3086121A1 - ROTOR FOR ASYNCHRONOUS ELECTRIC MACHINE WITH NON-THROUGH SHAFT - Google Patents

Abstract

This rotor for an asynchronous electric machine with a non-traversing shaft comprises two half-shafts (11, 12) enclosing a cylindrical magnetic mass (13) and two short-circuit discs (14) each inserted between a different half-shaft and one of the ends. of the cylindrical magnetic mass. Each half-shaft comprises at least a first retaining means, each short-circuit disc comprises on each of its faces at least a second retaining means and each end of the magnetic mass comprises at least a third retaining means, the first, second and third retaining means cooperating with each other so as to prevent relative movement of the short-circuit discs with respect to the half-shafts and with respect to the magnetic mass.

Description

Rotor for asynchronous electric machine with non-through shaft

The present invention relates to asynchronous rotating electrical machines with squirrel cage and relates more particularly to a device for blocking sheets incorporated in a rotor of the machine comprising a non-traversing shaft.

The present invention also relates to a rotary electric machine comprising such a rotor.

Generally a rotor of an asynchronous rotating electrical machine comprises a laminated rotor intended to operate at high rotational speeds, in particular up to a peripheral speed of 300 m / s, and comprises a non-traversing shaft so that the magnetic sheets of the rotor do not have a recess in their center in order to minimize the mechanical stresses which, in the case of a rotor comprising a through shaft, are concentrated around the recess and are liable to damage the sheets of the magnetic circuit.

The document EP0609645 describes a laminated rotor comprising a non-traversing shaft for an asynchronous electric motor.

Referring to Figure 1 which shows a section of such a rotor 1 in an axial direction.

The rotor comprises two half-shafts 2 and 3 between which are inserted magnetic sheets 4 kept compacted by tie rods 5 connecting the two half-shafts 2 and 3.

The magnetic sheets 4 form the magnetic mass of the rotor.

The rotor 1 comprises respectively short-circuit crowns or discs 2a and 3a connecting conductive bars (not shown), for example made of copper, forming a squirrel cage.

Each magnetic sheet 4 comprises holes 4a into which the tie rods 5 are inserted and has a thickness generally between one tenth of a millimeter and one millimeter.

Each sheet 4 is coated with a layer of insulating varnish 6 preventing electrical contact between adjacent sheets so as to minimize the eddy current losses and increase the efficiency of the motor.

The holes 4a are dimensioned so that the tie rods 5 can be inserted into the holes 4a of the set of sheets 4 stacked during the construction of the rotor and so that a clearance remains to absorb the increase in the diameter of the tie rods under the effect of heat during operation of the rotor.

The magnetic sheets 4 are held together by shear adhesion under the effect of the compacting of the sheets, the presence of roughness on the surface of the magnetic sheets and the electrically insulating varnish.

However, when the engine is started and stopped, it goes through a critical bending speed corresponding to the first proper mode of the rotor.

When the critical speed of flexion is reached, the rotor flexes and vibrates.

In addition, during engine operation, the rotor is subjected to vibrations, shocks and thermal overheating.

Furthermore, the asynchronous rotating electric machine can be used in a chemically aggressive environment causing deterioration of the varnish covering the magnetic sheets, for example when the electric machine is used and incorporated in a motor-compressor.

In this application, the rotor is cooled by the gas containing impurities and / or aggressive chemical components deteriorating the varnish before its compression and liable to damage the magnetic sheets.

These phenomena are likely to cause a radial sliding of the sheets resulting in a radial clearance J between the magnetic sheets.

The two half-shafts are no longer coaxial as shown in Figure 2 causing strong vibrations of the rotor which can cause an emergency stop, see destruction of the rotor.

Reference may be made to documents US2003098627, EP0225440, US20110169355 and US20160186603 which disclose a monobloc rotor for an asynchronous electric machine comprising a shaft and a magnetic mass machined from the same block of material.

However, such a rotor requires machining operations which are costly in time and in raw material.

In addition, such a rotor cannot be dismantled, in particular for its transport and handling, making any replacement operation for example of a half-shaft impossible.

Document DE19956042 discloses a rotor with a non-traversing shaft for an asynchronous rotating electric machine comprising a magnetic mass formed by a stack of metal plates compacted between two half-shafts.

The metal plates have a thickness greater than that of the magnetic sheets. The plates are less prone to chemical attack.

However the sheets are maintained by adhesion.

Under the effect of centrifugal force or shock and vibration, the sheets can move in a radial direction.

Document DE573512 discloses a rotor for a turbogenerator comprising a magnetic mass formed of metal plates stacked and welded together.

Each sheet has a pin projecting from a first face and a cavity formed in a second face, the pin and the cavity cooperating respectively with a cavity and a pin of the adjacent sheets.

However, this rotor is not suitable for an asynchronous rotating electric machine.

In addition, the magnetic circuit is maintained by welding the metal plates together, and not by compacting between two half-shafts using tie rods or screws.

Document EP05091 19 discloses a rotor for an asynchronous rotary electrical machine comprising a magnetic mass formed by a stack of welded sheets.

However the sheets are crossed by a tree.

Documents JPH104658 and WO2018037486 disclose a rotor for an asynchronous rotating electric machine comprising a one-piece magnetic mass traversed by a shaft.

In document US Pat. No. 6,567,778, a rotor for an asynchronous electric machine is formed from a shaft on which copper elements are inserted so as to form a squirrel cage by a process of the hot isostatic compression type.

Such a process is expensive and requires an oven for the production of the rotor.

The ovens are not suitable for large rotors, for example one meter in outside diameter and six meters in length.

In addition, such a rotor is not removable in several parts since it is in one piece.

It is therefore proposed to overcome the drawbacks of one-piece rotors or to a one-piece magnetic mass or comprising stacks of metal plates.

In view of the above, there is proposed, according to one aspect, a rotor for an asynchronous electric machine with a non-traversing shaft comprising two half-shafts enclosing a cylindrical magnetic mass and two short-circuit disks each inserted between a half-shaft and a of the ends of the cylindrical magnetic mass.

Each half-shaft comprises at least a first retaining means, each short-circuit disc comprises on each of its faces at least a second retaining means and each end of the magnetic mass comprises at least a third retaining means, the first, second and third retaining means cooperating with each other so as to prevent relative movement of the short-circuit discs with respect to the half-shafts and with respect to the magnetic mass.

This prevents, or limits the radial sliding of the sheets in the rotor and so that the rotor is removable.

According to one embodiment, tie rods are distributed uniformly over at least one diameter of the rotor so as to keep the magnetic mass and the short-circuit discs compacted between the half-shafts.

According to another embodiment, screws are distributed uniformly over a diameter of the half-shafts passing through the short-circuit discs and engaged in the magnetic mass so that the half-shafts enclose the short-circuit discs and the magnetic mass.

Preferably, the first, second and third retaining means are arranged in the center of the short-circuit disc, the half-shaft and the magnetic mass.

Advantageously, the first, second and third retaining means are arranged uniformly or substantially uniformly distributed over the same diameter of the short-circuit disc, the half-shaft and the magnetic mass.

Preferably, the first retaining means and the third retaining means each comprise a counterbore and the second retaining means comprises a retaining pin intended to be inserted into the counterbore.

Advantageously, the short-circuit disc and the retaining pin are hollowed out in their center.

According to one characteristic, the first retaining means and the third retaining means each comprise a retaining pin and the second retaining means comprises a counterbore intended to receive the retaining pin.

Preferably, the first retaining means comprises a retaining pin, the third retaining means comprises a counterbore, the second retaining means of a first face of the short-circuit disc comprises a counterbore and the second retaining means a second face of the short circuit disc includes a retaining pin so that each retaining pin is inserted in an adjacent counterbore.

Advantageously, the rotor further comprises at least one removable retaining pin, the first, the second and the third retaining means each comprising a countersink cooperating with the removable retaining pin.

Preferably, the rotor also comprises at least one removable retaining pin, and the first retaining means comprises a blind hole made in the half-shaft, the second retaining means comprises a hole made in the short-circuit disc of so that the short-circuit disc is traversed by the hole and the third retaining means comprises a hole made in the magnetic mass so that the magnetic mass is traversed by the hole, the removable retaining pin being inserted with or without play in the holes.

Advantageously, the retaining pin or the removable retaining pin is circular in cylindrical or conical shape, or polygonal, preferably square, triangular or square surmounted by a triangle.

According to another embodiment, the magnetic mass comprises a one-piece metallic body.

According to yet another embodiment, the magnetic mass comprises a stack of metal plates, each metal plate comprising on each of its faces a retaining means, the adjacent retaining means being intended to cooperate with each other so as to prevent relative displacement of a metal plate with respect to the adjacent elements comprising a metal plate or a short-circuit disc.

Preferably, the rotor further comprises screws distributed in the metal plates comprising counterbores so as to secure adjacent metal plates, the screw heads being housed in the counterbores.

Advantageously, an electrical insulator is inserted between the half-shaft and the short-circuit disc and / or inserted between the metal plates.

Preferably, the rotor also comprises bars inserted uniformly over the same diameter of the magnetic mass, the retaining pin or the removable retaining pin being of polygonal shape and placed in the center of the magnetic mass, the number of faces of the polygon being a multiple of the number of bars and tie rods.

Advantageously, the retaining means are arranged uniformly over at least one diameter of the magnetic mass.

Preferably, the first, second and third retaining means are of different types.

According to another aspect, an asynchronous rotating electric machine with squirrel cage is proposed comprising a rotor as defined above.

Other characteristics and advantages of the invention will appear on reading the following description of embodiments of the invention, given only by way of nonlimiting examples and with reference to the drawings in which:

- Figures 1 and 2, which have already been mentioned, illustrate a rotor comprising a non-through shaft of an electric rotary machine according to the state of the art;

- Figure 3 illustrates an embodiment of an asynchronous rotating electrical machine;

- Figure 4 illustrates a section in an axial direction of a first embodiment of the rotor;

- Figure 5 illustrates a partial section along an axial direction of a second embodiment of the rotor;

- Figure 6 illustrates a partial section along an axial direction of a third embodiment of the rotor;

- Figure 7 illustrates a partial section along an axial direction of a fourth embodiment of the rotor;

- Figure 8 illustrates a partial section along an axial direction of a fifth embodiment of the rotor;

- Figure 9 illustrates a partial section along an axial direction of a sixth embodiment of the rotor;

- Figure 10 illustrates a section along an axial direction of a seventh embodiment of the rotor;

- Figure 11 illustrates a section along an axial direction of an eighth embodiment of the rotor;

- Figure 12 illustrates a partial section along an axial direction of a ninth embodiment of the rotor;

- Figure 13 illustrates a partial section along an axial direction of a tenth embodiment of the rotor;

- Figure 14 illustrates an embodiment of metal plates held by screws;

- Figures 15 and 16 illustrate an eleventh embodiment of the rotor; and

- Figures 17 to 19 illustrate embodiments of the short-circuit disc.

Reference is made to FIG. 3 which illustrates an embodiment of an asynchronous rotary electrical machine 7 comprising a stator 8, bearings 9 and a rotor 10 inserted in the stator 8 and the bearings 9.

The rotor 10 comprises a non-traversing rotor shaft comprising two half-shafts 11 and 12 and an axis (A) coincident with the axis of rotation of the rotor 10.

As can be seen in FIG. 4, the rotor 10 further comprises a magnetic mass 13, two short-circuit disks 14 each inserted between one end of the magnetic mass 13 and a half-shaft 11, 12.

Bars 15 are inserted uniformly over the same diameter in the magnetic mass 13.

The bars 15 and the short-circuit disks 14 are made for example of copper and are electrically connected together to form a squirrel cage.

In this embodiment, the magnetic mass 13 comprises a one-piece metallic body made, for example, of steel.

Tie rods 16 are distributed uniformly over a diameter of the rotor so as to keep the magnetic mass 13 and the short-circuit discs 14 compacted between the two half-shafts 11 and 12.

The ends of the tie rods 16 have a thread in order to receive a nut.

The magnetic mass 13, the short-circuit discs 14 and the half-shafts 11 and 12 have through holes for the tie rods 16 which are dimensioned so that when the rotor heats up, the tie rods can expand under the 'effect of heat, but also to allow insertion with a game of tie rods in the magnetic mass.

Each half-shaft 11 and 12 comprises at least a first retaining means, each short-circuit disc 14 comprises on each of its faces at least a second retaining means and each end of the magnetic mass comprises at least a third retaining means detention.

The first, second and third retaining means cooperate with each other so as to prevent relative movement of a short-circuit disc 14 relative to the half-shafts 11 and 12 and relative to the magnetic mass 13.

In this embodiment, the first, second and third retaining means are disposed respectively in the center of the half-shaft 11 and 12, in the center of the short-circuit disc 14, and in the center of the magnetic mass 13.

The first and third retaining means comprise a counterbore 17, 20 and the second retaining means comprises a retaining pin 18, the pegs 18 and the counterbores 17 and 20 are dimensioned so that the pin 18 is inserted into the counterbore 17 , 20 with or without clearance.

In what follows, elements identical to those described above are identified by the same reference numerals.

Referring to Figure 5 which illustrates a partial section along an axial direction of a second embodiment of the rotor 10

We find the magnetic mass 13, the short-circuit disc 14, the bars 15, the tie rods 16, the retaining pins 18 and the counterbores 20.

In this embodiment, an electrical insulator 21 separates the magnetic mass 13 and the short-circuit disc 14 on a part of their contact surface.

The electrical insulator 21 is composed of a crown with a hole opposite each pin 18 for the passage of the pin 18, and a disc facing each pin 18.

In a variant not shown, the electrical insulator is an insulating varnish deposited on a thin sheet, for example made of steel, the thin sheet comprising a crown and a disc opposite each pin 18 being inserted between the magnetic mass 13 and the disc of short circuit 14.

Likewise, in a variant not shown, the insulator 21 comprising an insulating ring and an insulating disc opposite each pin 18, or an insulating varnish deposited on a thin sheet, is inserted between each metal plate as shown in FIGS. 10 to 14, which limits the leakage currents in order to improve the efficiency of the rotary electric machine 7.

The partial electrical insulation between the magnetic mass 13 and the short-circuit discs 14 makes it possible to reduce the leakage currents.

Consequently, the heating of the rotor 10 is reduced.

The efficiency of the rotary electric machine 7 is improved.

Reference is made to FIG. 6 which illustrates a partial section along an axial direction of a third embodiment of the rotor 10.

We find the magnetic mass 13, the bars 15, the tie rods 16, the retaining pins 23 and the counterbores 20.

In this embodiment, the short-circuit disc 14 is hollowed out at its center and the second means for retaining the short-circuit disc 14 comprises a retaining pin 23 hollowed out at its center so as to form two retaining collars intended to be inserted each with or without play in the counterbore 20.

These recesses make it possible to reduce the quantity of copper so as to lighten the mass of the rotor 10.

This reduction makes it possible to increase the value of the critical speed of rotation in bending of the rotor 10, this making it possible to increase the operating speed of the rotary electric machine 7 and consequently its electric power.

According to a fourth embodiment of the rotor 10, visible in FIG. 7, screws 24 are distributed uniformly over a diameter of the half-shafts 11 and 12 and pass through the short-circuit discs 14.

The screws 24 are engaged in the magnetic mass 13 so that the half-shafts 11 and 12 enclose the short-circuit discs 14 and the magnetic mass 13.

According to a fifth embodiment (FIG. 8), the first retaining means and the third retaining means each comprise a retaining pin 25 and 27, and the second retaining means comprises a counterbore 26.

The retaining studs 25 and 27 and the counterbore 26 are dimensioned so that the retaining studs fit into a counterbore.

Reference is made to FIG. 9 which illustrates a sixth embodiment of the rotor 10.

In this embodiment, the first retaining means comprises a retaining pin 28, the third retaining means comprises a counterbore 31, the second retaining means of a first face of the short-circuit disc comprises a counterbore 29 and the second means for retaining a second face of the short circuit disc comprises a retaining pin 30.

The retaining pin 28 of the half-shaft 11, the counterbore 29 and the retaining pin 30 of the short-circuit disc, and the counterbore 31 of the magnetic mass 13 are dimensioned so that the retaining pins each fit into counterbore with or without play.

Reference is made to FIG. 10 which illustrates a section along an axial direction of a seventh embodiment of the rotor 10.

We find the half-shafts 11 and 12 comprising the countersinks 20, the short-circuit discs 14 comprising the retaining pins 18, the bars 15 and the tie rods 16.

The rotor 10 comprises a magnetic mass 32 comprising a stack of metal plates 33 and 34.

The metal plate referenced 34 is located at one end of the magnetic mass 32.

Each metal plate 33 and 34 has on each of its faces a retaining means.

The means for retaining the plate referenced 33 comprise a counterbore 35 on a first face of said plate and on a second face a retaining pin 36 so that the retaining pin 36 is inserted with or without play in an adjacent counterbore 35 or so that for a plate 33 located at the end of the magnetic mass 32 the retaining pin 18 of the short-circuit disc 14 is inserted with or without play in a countersink 35 of said plate 33.

The means for retaining the first and second faces of the metal plate being able to cooperate with or without play with the means for retaining the adjacent plates so as to prevent relative movement of the metal plate relative to the adjacent metal plates 33, 34.

The plate referenced 34 comprises on each of its faces a counterbore 35 so that the retaining pin 18 and 36 is inserted with or without play in an adjacent counterbore 35.

The plate referenced 34 comprises the third retaining means cooperating with the second means for retaining the short-circuit disc 14 comprising the pin 18 so as to prevent relative movement of the metal plate referenced 34 relative to an adjacent element comprising the plate metallic referenced 33 or the short-circuit disc 14.

According to an eighth embodiment of the rotor 10, visible in FIG. 11, on which there are the half-shafts 11 and 12 comprising the countersinks 20, the short-circuit discs 14 comprising the retaining pins 18, the bars 15 and the tie rods 16, the rotor 10 comprises a magnetic mass 36 comprising a stack of metal plates 37 and 38, alternately.

The metal plates 37 and 38 each have on their first and second faces an identical retaining means.

The means for retaining the plates referenced 37 comprises a counterbore on each face and the means for retaining the plates referenced 38 comprises a pin on each face.

The plates referenced 37 and 38 are stacked alternately so that a pin is inserted with or without play in an adjacent counterbore and so that the third means for retaining the plates 37 at the end of the magnetic mass cooperate with the second means for retaining the short-circuit disc 14 so as to prevent a relative displacement of a metal plate with respect to an adjacent element comprising a metal plate 37, 38 or the short-circuit disc 14.

In the embodiment of FIG. 12, the rotor 10 comprises a magnetic mass 39 comprising a stack of metal plates 40.

Each metal plate 40 comprises on each of its faces a retaining means comprising a counterbore 41 receiving with or without play a removable retaining pin 42 so as to prevent relative movement of the metal plate relative to the adjacent metal plates.

The plates 40 situated at the ends of the magnetic mass 39 each comprise the third retaining means cooperating with the second means for retaining the short-circuit disc 14 so as to prevent a relative displacement of the metal plate with respect to the short disc - circuit 14.

In this embodiment, the first, second and third retaining means each include a counterbore identical to the counterbore 41 receiving a removable retaining pin 42.

The removable retaining pin 42 can, if it is secured to one side or both sides of a metal plate 40, be glued to the plate or shrunk into the counterbore 41 of the plate. If the pin is shrunk, the temperature difference necessary for shrinking is obtained either by heating the plate or preferably by cooling the removable pin, for example by immersing the pin in liquid nitrogen.

According to other embodiments, the first, the second and the third retaining means can be of different types.

Reference is made to FIG. 13 which illustrates a partial section along an axial direction of a tenth embodiment of the rotor

10.

In this embodiment, the rotor 10 comprises a magnetic mass 43 comprising a stack of metal plates 44.

Each metal plate 44 includes through holes 45 so that each hole 45 cooperates with or without play with a removable retaining pin 46 so as to prevent relative movement of a metal plate 44 relative to the adjacent metal plates.

The plates 44 situated at the ends of the magnetic mass 43 each comprise the third retaining means comprising a hole 45 cooperating with the second retaining means of the short-circuit disc 14 so as to prevent relative movement of the metal plate with respect to short circuit disc 14.

In this embodiment, the first retaining means comprises a blind hole 48, the second retaining means comprises a hole 49 so that the short-circuit disc 14 is crossed by the hole 49, a removable retaining pin 50 s '' inserting with or without play in the holes referenced 45, 48 and 49.

According to other embodiments, the first, second and third retaining means can be of different types.

According to another embodiment, the retaining pins referenced 46 and 50 are replaced by a rod 47 fitting with or without play in the holes 45, 49 and being housed in the blind holes 48.

In the embodiments of the rotor 10 comprising metal plates described above, the metal plates are held in the axial direction (A) by the tie rods.

Alternatively, the metal plates are screwed together.

As shown in Figure 14 the metal plates 51, 52 and 53 can be held in place by screws.

In this case, the plates 51 and 52 each have a countersink 54 in order to embed the screw head 56 in the thickness of the plate and the plates 52 and 53 each comprise a tapping 55.

Screws 56 secure the plates 51, 52 and 53 together by being screwed into the internal threads 55.

The number and location of the screws are determined so that a metal plate does not move relative to the other metal plates when the rotor 10 is rotated and subjected to a torque or an over-torque applied to its half - trees.

Each plate 51, 52, 53 alternately has counterbores 54 for the passage of screws 56 and threads 55 cooperating with the threaded part of the screws 56. Thus each plate is fixed by screws and secured to the adjacent plates.

In a variant not shown, the metal plates are secured by compacting with tie rods connecting the two plates situated at the ends of the magnetic mass, the plates having holes for passage of the tie rods, and the two end plates comprising counterbores for receiving the nuts at the ends of the tie rods, or one of the two plates having threaded holes receiving the threaded end of the tie rods. Then the magnetic mass is fixed by screws to the half-shafts as illustrated in Figure 7.

In the embodiments of the rotor 10 comprising metal plates described above, the metal plates can be of the same thickness or of different thicknesses.

The thickness of the metal plates is chosen so that it is greater than 40% of the thickness of the short-circuit disc 14 and greater than 5% of the external diameter of the rotor 10, preferably from 15 to 60% of the external diameter of the rotor.

According to other embodiments, retaining means are arranged uniformly over at least one diameter of the magnetic mass.

Figures 15 and 16 illustrate a partial section in an axial direction of an eleventh embodiment of the rotor 10 and a front view of the short-circuit disc 14 in the direction XVI.

We find the half-shaft 12 comprising the blind holes 48, the short-circuit disc 14 comprising the through holes 49 and removable retaining pins 57.

In this embodiment, the three removable retaining pins 57 are cylindrical and are arranged on the same diameter of the short-circuit disc 14, it is also possible, in variants not shown, to have 2, 4, 5 and more retaining pins machined in half-shafts or metal plates or short-circuit discs or removable pins, substantially uniformly distributed over the same diameter, or over two or more rows with two or more concentric diameters.

The retaining pins and the removable retaining pins can for example be circular in cylindrical or conical shape, square, in rhombus, triangular, trapezoidal, square surmounted by a triangle, polygonal.

Figures 17 and 18 illustrate a front view of the short-circuit disc 14 comprising the second retaining means in its center, or a front view of a half-shaft 11, 12 or a metal plate 13, 33 , 34, 37, 38, 40, 44, 51, 52, 53 of the magnetic mass.

FIG. 17 illustrates for example the first retaining means comprising a machined or removable square retaining pin 58 and the second retaining means comprising a square hole 59 receiving with or without play J the retaining pin 58.

The tie rods 16 pass through the short-circuit discs 14, the half-shafts or metal plates.

The number of faces of the pin 58 is a multiple of the number of copper bars 15 not shown in FIG. 17 and of tie rods 16 thus allowing several angular positions of the half-shaft or short-circuit disc or metal plates, during the stacking and manufacturing the rotor. As illustrated in FIG. 17, a square pawn with four faces is a multiple of eight tie rods, or as illustrated in FIG. 18, a triangular pawn with three faces is multiple and compatible with six tie rods.

Advantageously, this configuration makes it possible to avoid using polarizers when mounting the rotor.

In addition, such a retaining pin, machined or removable, makes it possible to transmit a large torque between the short-circuit disk 14 and the half-shaft, or between metal plates, by the faces of the polygon.

According to another embodiment, the removable or machined retaining pin may be a non-symmetrical polygon such as for example a square surmounted by a triangle, making it possible to use it as a polarizer as well as a single angular position if necessary of the half shaft, or short circuit disc, or metal plates.

The compaction force of the tie rods can be reduced because the torque only passes through the surfaces of the plates in contact. Thus, the number of tie rods can be reduced or the cross section of the tie rods can be reduced in the case of a rotor comprising tie rods.

Advantageously, retaining pins of polygonal shape allow the rotor to transmit a much higher torque than a transmission of torque by adhesion between adjacent elements such as half-shafts, short-circuit discs or metal plates.

FIG. 18 illustrates the first retaining means comprising a triangular pin 60 machined or removable, and the second or third corresponding retaining means comprising a triangular hole 61 accommodating with or without play J1 the pin 60, and the tie rods 16.

The number of faces of the pin 60 is a multiple of the number of tie rods 16 and of the copper bars 15 not shown in the figure

18.

In a variant not shown in FIGS. 4 to 6, 10 and 11, one threaded end of the tie rods 16 is screwed into a tapped hole in the half shaft 11 or 12, and the other end of the tie rods passes through a hole in the half shaft 12 or 11 to accommodate a nut.

FIG. 19 illustrates an alternative embodiment with two or more rows of copper bars 15 arranged on two or more substantially concentric diameters, or two or more rows of tie rods 16 or fixing screws 24, 56 disposed on two or more substantially concentric diameters .

In variants not shown, the bars 15 are rectangular, rectangular with rounded edges or oblong.

The bars 15 are preferably made of copper or alloyed copper but can also be made of aluminum, alloyed aluminum or any other electrically conductive material.

Claims (20)

1. Rotor for an asynchronous electric machine with a non-traversing shaft comprising two half-shafts (11, 12) enclosing a cylindrical magnetic mass (13) and two short-circuit discs (14) each interposed between a half-shaft and one of the ends of the cylindrical magnetic mass, characterized in that each half-shaft comprises at least a first retaining means, each short-circuit disc comprises on each of its faces at least a second retaining means and each end of the magnetic mass comprises at at least a third retaining means, the first, second and third retaining means cooperating with one another so as to prevent a relative displacement of the short-circuit disks with respect to the half-shafts and with respect to the magnetic mass. 2. Rotor according to claim 1 further comprising tie rods (16) uniformly distributed over at least one diameter of the rotor (10) so as to keep the magnetic mass (13) and the short-circuit disks (14) compacted between the half-trees (11, 12). 3. Rotor according to claim 1 further comprising screws (24) uniformly distributed over a diameter of the half-shafts (11, 12) passing through the short-circuit discs (14) and engaged in the magnetic mass so that the half-shafts enclose the short-circuit discs and the magnetic mass (13). 4. Rotor according to claim 1 to 3, wherein the first, second and third retaining means are arranged in the center of the short-circuit disc (14), the half-shaft (11, 12) and the magnetic mass ( 13). 5. Rotor according to claim 1 to 3, wherein the first, second and third retaining means are arranged uniformly or substantially uniformly distributed over the same diameter of the short-circuit disc (14), the half-shaft (11 , 12) and the magnetic mass (13). 6. Rotor according to one of claims 1 to 5, wherein the first retaining means and the third retaining means each comprise a counterbore (17, 20) and the second retaining means comprises a retaining pin (18) for to fit into the counterbore. 7. Rotor according to claim 6, wherein the short circuit disc (14) and the retaining pin (23) are recessed in their center. 8. Rotor according to one of claims 1 to 5, wherein the first retaining means and the third retaining means each comprise a retaining pin (25, 27) and the second retaining means comprises a counterbore (26) for to receive the retaining piece. 9. Rotor according to one of claims 1 to 5, wherein the first retaining means comprises a retaining pin (28), the third retaining means comprises a countersink (31), the second retaining means of a first face of the short-circuit disc comprises a counterbore (29) and the second means for retaining a second face of the short-circuit disc comprises a retaining pin (30) so that each retaining pin is inserted into a counterbore adjacent. 10. Rotor according to one of claims 1 to 5, further comprising at least one removable retaining pin (42), the first, the second and the third retaining means each comprising a countersink (41) cooperating with the pin removable retainer. 11. Rotor according to one of claims 1 to 5, further comprising at least one removable retaining pin (50, 46), and the first retaining means comprises a blind hole (48) made in the half-shaft, the second retaining means comprises a hole (49) made in the short-circuit disc (14) so that the short-circuit disc is traversed by the hole and the third retaining means comprises a hole (45) made in the magnetic mass (43) so that the magnetic mass passes through the hole, the removable retaining pin being inserted with or without play in the holes. 12. Rotor according to one of claims 6 to 11, wherein the retaining pin or the removable retaining pin is circular in cylindrical or conical shape, or polygonal, preferably square, triangular or square surmounted by a triangle. 13. Rotor according to one of claims 1 to 12, wherein the magnetic mass (13) comprises a one-piece metal body. 14. Rotor according to one of claims 1 to 12, wherein the magnetic mass (13) comprises a stack of metal plates (33, 34, 37, 38, 40, 44, 51, 52, 53) each metal plate comprising on each of its faces a retaining means, the adjacent retaining means being intended to cooperate with each other so as to prevent a relative displacement of a metal plate relative to the adjacent elements comprising a metal plate (33, 34, 37, 38 , 40, 44, 51, 52, 53) or a short-circuit disk (14). 15. Rotor according to claim 14, further comprising screws (56) distributed in the metal plates (51, 52, 53) having counterbores (54) so as to secure adjacent metal plates, the screw heads being housed in counterbores. 16. Rotor according to any one of claims 1 to 15, in which an electrical insulator (21) is inserted between the half-shaft (11, 12) and the short-circuit disc (14) and / or inserted between the metal plates. 17. Rotor according to any one of claims 6 to 16, further comprising bars (15) inserted uniformly on the same diameter of the magnetic mass, the retaining pin (58, 60) or the removable retaining pin ( 58, 60) being of polygonal shape and arranged in the center of the magnetic mass (13), the number of faces of the polygon being a multiple of the number of bars (15) and tie rods (16). 10 18. Rotor according to any one of claims 1 to 16, in which retaining means are arranged uniformly over at least one diameter of the magnetic mass. 19. Rotor according to one of claims 1 to 18, wherein the first, second and third retaining means are 15 different types. 20. Asynchronous rotating electric squirrel cage machine comprising a rotor according to any one of the preceding claims.